Container image trust is a policy decision that controls which registries, repositories, images, and signing keys Podman accepts. It provides a security boundary for image pulls and helps avoid disabling isolation with --privileged when access is denied. section 11.0 section 11.3
Podman evaluates trust policies from the most specific scope to the least specific:
- Define policy for a specific signed image, repository, registry, or the default scope. section 11.3
- Store the policy in /etc/containers/policy.json; run podman image trust commands as root on Linux. section 11.3
Reject a registry, then allow one repository
sudo podman image trust set -t reject docker.io sudo podman image trust set -t accept docker.io/library podman pull alpine The first policy rejects Docker Hub broadly; the more-specific docker.io/library rule allows the alpine pull while other repositories remain blocked. section 11.3
Require signed images
Configure a sigstore, export the signer’s public GPG key, and require it for a repository with podman image trust set -f /tmp/publickey.gpg quay.io/rhatdan. A signed image pulls successfully; an unsigned image from the same repository fails. section 11.3.1
